Chymotrypsin () is a proteolytic enzyme which cleaves peptide bonds. The enzyme shows selectively to peptides with aromatic sidechains on the carboxyl side of the peptide bond. This is due to a “hydrophobic pocket” near the active site of the enzyme. The protein also contains a large number of cationic residues.

In this depiction, , the cationic amino acid residues on the protein (blue) can interact with anionic, functionalized nanoparticles. After the nanoparticle-protein complex is formed, chymotrypsin then displays a preference for cationic substrates due to interaction with the anionic nanoparticle. The active site of chymotrypsin is shown in red.

Molecular Playground banner: Chymotrypsin is a digestive enzyme that breaks down proteins

References

You C-C, Agasti SS, De M, Knapp MJ, Rotello VM. Modulation of the Catalytic Behavior of α-Chymotrypsin at Monolayer-Protected Nanoparticle Surfaces. Journal of the American Chemical Society 2006; 128:14612-14618.